1. Field of the Invention
This invention generally relates to an adhesive article employing a switchable pressure sensitive adhesive (PSA) that is suitable for attachment to the skin and a method for using the same. In another aspect, the invention concerns a water-dispersible PSA composition comprising a physical mixture of one or more amphiphilic polyesters and a humectant.
2. Description of the Prior Art
Pressure-sensitive adhesives are used in a variety of industrial, consumer, and medical applications. Medical-use PSA are applied to a variety of backings for use as occlusive or non-occlusive adhesive articles such as bandages, wound dressings, analgesic or transdermal drug delivery patches, monitoring sensors, stimulating electrodes, and the like. Desirably, the properties of the PSA allow the medical article to remain adhered to a wearer's skin despite changing conditions, such as movement or perspiration. Additionally, the article should be removable in a way that avoids irritating the wearer's skin. Minimizing skin damage upon removal is especially important in the case of a PSA article applied to sensitive areas or in situations wherein repeat article application is required.
The objectives of improving the tack of a PSA while reducing skin irritation caused by the removal of the PSA article seemingly conflict because generally, superior adhesion increases the risk of intensifying removal trauma. One proposed solution is to utilize adhesive compositions that include latex and/or acrylic. Not only do articles employing these adhesives fail to minimize skin damage during removal, but the use of latex and/or acrylic polymers precludes the use of these articles by people with latex and/or acrylic skin allergies. Another proposed solution is to use medical articles employing a PSA that is “deactivated” by contact with a chemical or through temperature change or exposure to radiation. Typically, however, the deactivation chemical is a harsh, skin-irritating solvent and exposure to heat, cold, and/or radiation is often inconvenient and/or not suitable for the affected area.
Thus, a need exists for a robust, medical-use pressure sensitive adhesive article that can be conveniently removed in a way that avoids irritating the wearer's skin.